Semiconductor devices are electronic devices including semiconductor elements and the like exploiting electric properties of semiconductor materials. Such semiconductor devices have been widely used in audio equipment, communication equipment, computers, electric appliances, and the like. Particularly, semiconductor devices including a circuit element having a MOS (metal oxide semiconductor) structure, a TFT (thin film transistor), and the like, allows display devices such as a LCD to provide high-resolution image display and high-speed moving image display.
For such system LCDs, a reduction in electric power consumption and higher-resolution and higher-speed image display are needed. Along with this, downsize of a peripheral driving circuit of such system LCDs is also needed. Specifically, peripheral driving circuits with sub-micron design rules, i.e., circuits on which wirings are finely patterned like ICs, are needed. Further, also in order to increase carrier mobility in a semiconductor layer, the semiconductor elements also need to be finely patterned.
However, it is difficult to form such high-performance semiconductor elements of submicron order directly on a glass or quartz substrate, which is typically used in display devices such as a LCD device. For example, Patent Document 1 discloses a method of arranging a TFT on a glass substrate, by initially forming a TFT on a semiconductor substrate, and transferring the TFT onto a glass substrate by separating it from the semiconductor substrate. This method allows a highly-integrated and high performance semiconductor device including a single crystal silicon functional layer to be formed on a glass substrate and the like.
With regard to methods of producing semiconductor substrates such as a SOI (silicon on insulator) substrate, for example, Patent Document 2 discloses, as a method of forming an ion implantation layer in a semiconductor substrate having a pattern structure formed thereon, a method of forming an ion implantation-adjusting layer on the pattern structure surface, thereby forming an ion implantation layer at a uniform depth.
[Patent Document 1]
    Japanese Kokai Publication No. 2006-294703[Patent Document 2]    Japanese Kokai Publication No. Hei-11-186186